In recent years, memory systems implementing a non-volatile memory have been widely used. As one of the memory systems, solid-state drives (SSDs) implementing a NAND flash memory are known. The SSDs are used as main storages of various computing devices.
In general, the NAND flash memory mounted in the SSD includes a plurality of NAND flash memory dies. These dies maybe operated in parallel. However, processes (e.g., a write operation, a read operation, and the like) for one die are sequentially performed. Thus, when a read request for a die that is performing a write operation, is received (i.e., when a die collision occurs), there are some cases where a reply time of the read request known as read latency is considerably longer than a typical read latency.
Accordingly, in order to improve the performance of the SSD, there is a need for new technology that improves tolerance to die collision, in particular when a read request is received for a die which is performing a write operation.